A conventional art is disclosed in, for example, Non-Patent Document 1. The conventional art will be described with reference to FIG. 6. FIG. 6 shows a principle and configuration of a conventional three-dimensional video display apparatus. In FIG. 6, a viewer has, on her/his left and right eyes, respectively, polarizing filters 12a and 12b which are different in polarization direction from each other, and the viewer sees a graphic 14a for a left screen and a graphic 14b for a right screen through a half mirror 13. The viewer sees an image 16a of a vertically-polarized light 15a with her/his left eye and an image 16b of a laterally-polarized light 15b with her/his right eye through the polarizing filters 12a and 12b, respectively, so that a stereoscopic effect is produced in a viewed image due to binocular parallax.    Non-Patent Document 1: “OYO HIKARI EREKUTORONIKUSU HANDO BUKKU” edited by Kenichi Noda, Takanori Okoshi, Oyo erekutoronikusu hando bukku henshuu iinkai, first edition, SHOKODO Co., Ltd., Apr. 10, 1989, p. 861